Cooling of high performance integrated circuits with high heat dissipation is presenting significant challenge in the electronics cooling arena. Conventional cooling with heat pipes and fan mounted heat sinks are not adequate for cooling chips with every increasing wattage requirements, including those exceeding 100 W.
Electronics servers, such as blade servers and rack servers, are being used in increasing numbers due to the higher processor performance per unit volume one can achieve. However, the high density of integrated circuits also leads to high thermal density, which is beyond the capability of conventional air-cooling methods.
A particular problem with cooling integrated circuits on electronics servers is that multiple electronics servers are typically mounted in close quarters within a server chassis. In such configurations, electronics servers are separated by a limited amount of space, thereby reducing the dimensions within which to provide an adequate cooling solution. Typically, stacking of electronics servers does not provide the mounting of large fans and heat sinks for each electronics server. Often each server within an electronics enclosure is cooled by a dedicated internal fan. For blade server applications, groups of blade servers are cooled by one or more internal fans dedicated to each group of blade servers. Using such configurations, the integrated circuits on each electronics server are cooled using fans that blow air over the integrated circuits on the electronics servers. However, considering the limitations of the internal fans within the server rack, the amount of air available for cooling the integrated circuits is limited.
Supplemental cooling is provided by Computer Room Air Conditioning (CRAC) units external to the electronics enclosure. Cooled air is vented through the electronics enclosure, entering from one side of the chassis and exiting an opposite side. As data centers continue to increase their computer density, electronics servers are being deployed more frequently. Fully populated electronics servers significantly increase rack heat production. This requires supplemental cooling beyond what the CRAC units can provide. Supplemental cooling systems may include fans, pump, and heat exchangers located outside the back end of the electronics server to decrease the air temperature exiting the electronics server. The heat exchangers in these supplemental cooling systems are supplied with pumped coolants, water, or refrigerants. Some supplemental cooling systems are configured as a “cooling door” that is attached to the back of an electronics enclosure. However, for some electronics enclosure there is typically uneven heat load throughout the electronics enclosure, which often leads to inadequate cooling of certain areas within the electronics enclosure, even when conventional supplemental cooling systems are used.